147 research outputs found
TEACHING COURSE - ARTERIOVENOUS MALFORMATIONS: Neurosurgical Treatment of Cerebral Arteriovenous Malformations
Expression of mRNA for phospholipase A(2), cyclooxygenases, and lipoxygenases in cultured human umbilical vascular endothelial and smooth muscle cells and in biopsies from umbilical arteries and veins
Arachidonic acid (AA) is released by phospholipase A(2) (PLA(2)) and then converted into vasoactive and inflammatory eicosanoids by cyclooxygenases (COX) and lipoxygenases (LOX). These eicosanoids are important paracrine regulators of vascular permeability, blood flow, local pro- and anticoagulant activity and they play a major role in the local inflammatory response. We have investigated the presence of mRNAs for PLA(2) and for isoforms of COX and LOX in both human endothelial cells (EC) and in human smooth muscle cells (SMC) in culture and in vascular biopsies of human umbilical veins (HUVB) and arteries (HUAB) by using the reversed transcription-polymerase chain reaction (RT-PCR) technique. Results show detectable levels of PLA(2) type IV (cPLA(2)) in cultured EC and SMC and in vascular wall biopsies from HUAB and HUVB. The cultured EC and SMC demonstrate higher levels of both COX-1 and COX-2 with PCR analyses than do vascular wall biopsies from HUAB and HUVB. This indicates a difference in the native expression of COX-1 and COX-2 in cultures of EC and SMC compared to that in biopsies from intact vessel walls. The EC and SMC in culture do not express mRNA for 5-LOX, that was, however, expressed in the vascular wall biopsies. This speaks in favour of a constitutive, i.e, in vivo expression of 5-LOX in SMC in the vascular wall of both umbilical vein and arteries. Thus results from in vitro studies of constitutive COX and LOX expression in EC and vascular SMC in culture cannot simply be extrapolated to represent in vivo conditions
Vascular endothelial growth factor production and regulation in rodent and human pituitary tumor cells in vitro
Angiogenesis, the formation of a new blood supply, is an essential step in tumorigenesis. Although vascular endothelial growth factor (VEGF) is known to be a very potent angiogenic factor in most solid tumors, little is known about its production and regulation in pituitary adenomas. We have investigated basal and stimulated VEGF production by rodent pituitary tumor cells (mouse corticotrope AtT20, rat lactosomatotrope GH3, mouse gonadotrope alpha T3-1 and mouse folliculostellate TtT/GF cells), and by hormone-inactive (27), corticotrope (9), lactotrope (3) and somatotrope (21) human pituitary adenoma cell cultures. All 4 pituitary cell lines secreted VEGF, which in the case of AtT20, GH3 and TtT/GF cells was inhibited by approximately 50% by dexamethasone. TtT/GF cells were the most responsive to the different stimuli used since basal values were augmented by pituitary adenylate cyclase activating polypeptide-38 (PACAP-38), interleukin-6 (IL-6), transforming growth factor-cc (TGF-a), IGF-I and the somatostatin analogue ocreotide. However, in GH3, AtT20 and aT3-1 cells, basal VEGF levels where not enhanced with any of the stimuli tested. The majority of the human adenomas tested (92%) basally secreted measurable VEGF which was inhibited by dexamethasone in most cases (84%). VEGF levels were increased in hormone inactive adenomas, somatotrope tumors and prolactinomas by TGF-alpha, PACAP-38, and 17 beta -estradiol, respectively. In conclusion, pituitary tumor cells are capable of producing VEGF which may be involved in tumoral angiogenesis. Our results concerning the suppression of VEGF by dexamethasone suggest that glucocorticoids may have anti-angiogenic properties and therefore therapeutic relevance for the treatment of pituitary adenomas
Hemicraniectomy for Dominant vs Nondominant Middle Cerebral Artery Infarction : A Systematic Review and Meta- Analysis
Objectives: Decompressive hemicraniectomy decreases mortality and severe disabil-ity from space-occupying middle cerebral artery infarction in selected patients. However, attitudes towards hemicraniectomy for dominant-hemispheric stroke have been hesitant. This systematic review and meta-analysis examines the associa-tion of stroke laterality with outcome after hemicraniectomy. Materials and methods: We performed a systematic literature search up to 6th February 2020 to retrieve original articles about hemicraniectomy for space-occupying middle cere-bral artery infarction that reported outcome in relation to laterality. The primary outcome was severe disability (modified Rankin Scale 4-6 or 5-6 or Glasgow Out -come Scale 1-3) or death. A two-stage combined individual patient and aggregate data meta-analysis evaluated the association between dominant-lateralized stroke and (a) short-term ( 3 months) outcome. We per -formed sensitivity analyses excluding studies with sheer mortality outcome, sec -ond-look strokectomy, low quality, or small sample size, and comparing populations from North America/Europe vs Asia/South America. Results: The analysis included 51 studies (46 observational studies, one nonrandomized trial, and four randomized controlled trials) comprising 2361 patients. We found no asso-ciation between dominant laterality and unfavorable short-term (OR 1.00, 95% CI 0.69-1.45) or long-term (OR 1.01, 95% CI 0.76-1.33) outcome. The results were unchanged in all sensitivity analyses. The grade of evidence was very low for short -term and low for long-term outcome. Conclusions: This meta-analysis suggests that patients with dominant-hemispheric stroke have equal outcome after hemicraniec-tomy compared to patients with nondominant stroke. Despite the shortcomings of the available evidence, our results do not support withholding hemicraniectomy based on stroke laterality.Peer reviewe
Acceptability of yogurt and yogurt-like products: influenceof product information and consumer characteristics and preferences
19 pages, 8 tables, 3 figures.-- Printed version published in July 2010.-- The definitive version is available at www3.interscience.wiley.comThis work aims to investigate whether the information about product type and the nutritional label affects consumer acceptability of yogurt and fermented milk. Hedonic evaluations of seven commercial samples, three yogurts and four fermented milks were elicited from 120 consumers under blind tasting conditions, looking at a card with the product type and with the label nutritional facts and finally, tasting labeled products. For the whole group of consumers, nutritional information did not affect the acceptability of these products although analysis of individual consumer behavior showed that only for around 50% of consumers surveyed, this result reflects on their actual response. When data for subgroups of consumers of different gender or age or with different preference pattern were considered, differences in the influence of nutritional information on samples acceptability were detected. These results confirm that the data averaged from the consumer whole population cannot accurately reflect the real behavior of the population surveyed. More complete and valid information can be gained from analyzing the responses of the consumer subgroups of different characteristics or with different individual preferences.To MICINN of Spain for financial support (Project AGL 2007-63444). To Fondo Social Europeo for financing the contract of author S. Bayarri in the program I3P from CSICPeer reviewe
The Effect of Genetic and Environmental Variation on Genital Size in Male Drosophila: Canalized but Developmentally Unstable
The genitalia of most male arthropods scale hypoallometrically with body size, that is they are more or less the same size across large and small individuals in a population. Such scaling is expected to arise when genital traits show less variation than somatic traits in response to factors that generate size variation among individuals in a population. Nevertheless, there have been few studies directly examining the relative sensitivity of genital and somatic traits to factors that affect their size. Such studies are key to understanding genital evolution and the evolution of morphological scaling relationships more generally. Previous studies indicate that the size of genital traits in male Drosophila melanogaster show a relatively low response to variation in environmental factors that affect trait size. Here we show that the size of genital traits in male fruit flies also exhibit a relatively low response to variation in genetic factors that affect trait size. Importantly, however, this low response is only to genetic factors that affect body and organ size systemically, not those that affect organ size autonomously. Further, we show that the genital traits do not show low levels of developmental instability, which is the response to stochastic developmental errors that also influence organ size autonomously. We discuss these results in the context of current hypotheses on the proximate and ultimate mechanisms that generate genital hypoallometry
Mating plugs in polyandrous giants: Which sex produces them, when, how and why?
10.1371/journal.pone.0040939PLoS ONE77
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